SecondLanguage lets you use Gettext files in .NET without a lot of hassle. It can read and write both .mo and .po, and fully supports message contexts and plural forms. A C-style printf formatter is included, so you don't have to use .NET-specific translations.

Easy I18N is a library that integrates GNU gettext with the JVM's internationalization facilities. Existing Java APIs (MessageFormat, DateFormat, Locale) are used to provide a much easier API for building and maintaining applications and Web apps. It includes the ability to use normal message strings in your code, use xgettext to auto-extract translatable strings, leverage the GNU gettext system and associated tools to manage translations, work with date, currency, and numeric input/output, supports thread-local Locales for Web apps (or global for apps), and more.

iLib is an internationalization library for JavaScript that was created because with the advent of AJAX, it is no longer possible to avoid internationalization. Previously, you could format dates in the user's locale on the server. Now, Web services called via AJAX return time stamps in Unix time and formatting has to be done in the browser, but the standard library is inadequate. In addition to dates, the library handles times, numbers, currency, percentages, calendar calculations (Arabic, Hebrew, Gregorian, and Julian), time zones, string translation, string formatting and choice formats, locale info, ctype functions, and Unicode normalization.

oTranCe offers a ready to go and entirely Web-based translation platform to your project and your translators. The files you already translated can be imported easily, and the present stage can be exported to language packages at any time. If you are using a versioning system you can, update your repository with just a mouse click. All your translators need is a login to start working on translations. The administrator will be able to adjust very fine-grained rights and roles for your developers and translators.

Weblate is a Web-based translation tool with tight Git integration. It features a simple and clean user interface, propagation of translations across subprojects, consistency checks, and automatic linking to source files.

libunibreak is an implementation of the line breaking and word breaking algorithms as described in Unicode Standard Annex 14 and Unicode Standard Annex 29. It is a superset of, and supersedes, liblinebreak. It is designed to be used in a generic text renderer. FBReader is one real-world example.

Colossal Mind Language Detector detects a user's preferred language. It parses the HTTP Accept-Language header and determines the most suitable language for the user from a list of supported languages. The detected language can fallback to a language associated with the user's country in case the Accept-Language header is not sent by the browser. The detected language can be stored in a cookie to avoid needing to detect the language again in subsequent requests.

Java Message Translator is a Web based i18n property file editor. When working with Java applications that need to be translated, it can be difficult to keep all the translated .properties-files up-to-date, as the translations usually need to be done by someone else.

BidiChecker is a tool for the automated testing of Web pages for errors in support of right-to-left (RTL) languages (also known as bidirectional/BiDi). It provides a JavaScript API to be called from automated test suites that regression-test live Web pages in a browser, usually using an automated testing framework such as JSUnit.